Positive Lookahead(?=class="four-column mosaicElement") class="four-column mosaicElement"the literal text class="four-column mosaicElement" (case sensitive) *?matches any number of characters from the set below:
\sany whitespace character
\Sany non-whitespace character
href="the literal text href=" (case sensitive) \s*any whitespace character, repeated any number of times
httpthe literal text http (case sensitive) s?optionally matches the literal s (11510 / 1638 / 7316) (case sensitive)
Negated Character Class[^\s]+ +matches at least one character outside the set below:
\sany whitespace character
\s*any whitespace character, repeated any number of times
"the literal " (3410 / 428 / 2216)
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string